Pancreatic cancer is a disease in which malignant (cancerous) cells form in the tissues of the pancreas. The pancreas is a gland located behind the stomach and in front of the spine. The pancreas produces digestive juices and hormones that regulate blood sugar. Cells called exocrine pancreas cells produce the digestive juices, while cells called endocrine pancreas cells produce the hormones. The majority of pancreatic cancers start in the exocrine cells.
Because the pancreas lies deep in the belly in front of the spine, pancreatic cancer often grows silently for months before it is discovered. Early symptoms and/or first signs can be absent or quite subtle. More easily identifiable symptoms develop once the tumor grows large enough to press on other nearby structures, such as nerves (which causes pain), the intestines (which affects appetite and causes nausea along with weight loss), or the bile ducts (which causes jaundice or a yellowing of the skin and can cause loss of appetite and itching). Symptoms in women rarely differ from those in men. Once the tumor sheds cancer cells into the blood and lymph systems and metastasizes, additional symptoms usually arise, depending on the location of the metastasis. Frequent sites of metastasis for pancreatic cancer include the liver, the lymph nodes, and the lining of the abdomen (called the peritoneum). Unfortunately, most pancreatic cancers are found after the cancer has grown or progressed beyond the pancreas or has metastasized to other places.
In general, the signs and symptoms of pancreatic cancer can be produced by exocrine or endocrine cancer cells. Exocrine pancreatic cancer signs and symptoms can include
pain in the abdomen or the back,
poor appetite and weight loss,
digestive problems (pale and/or greasy stools, nausea, and vomiting),
The signs and symptoms of endocrine pancreatic cancers are often related to the excess hormones that they produce and consequently to a variety of different symptoms. Such symptoms are related to the hormones and are as follows:
Insulinomas: Insulin-producing tumors that lower blood glucose levels can cause low blood sugars, weakness, confusion, coma, and even death.
Glucagonomas: Glucagon-producing tumors can increase glucose levels and cause symptoms of diabetes (thirst, increased urination, diarrhea and skin changes, especially a characteristic rash termed necrolytic migratory erythema).
Gastrinomas: Gastrin-producing tumors trigger the stomach to produce too much acid, which leads to ulcers, black tarry stools, and anemia.
Somatostatinomas: Somatostatin-producing tumors result in other hormones being overregulated and producing symptoms of diabetes, diarrhea, belly pain, jaundice, and possibly other problems.
VIPomas: These tumors produce a substance called vasoactive intestinal peptide (VIP) that may cause severe watery diarrhea and digestive problems along with high blood glucose levels.
PPomas: These tumors produce pancreatic polypeptide (PP) that affects both endocrine and exocrine functions, resulting in abdominal pain, enlarged livers, and watery diarrhea.
Carcinoid tumors: These tumors make serotonin or its precursor, 5-HTP, and may cause the carcinoid syndrome with symptoms of flushing of the skin, diarrhea, wheezing, and a rapid heart rate that occurs episodically; eventually, a heart murmur, shortness of breath, and weakness develop due to damage to the heart valves.
Nonfunctioning neuroendocrine tumors don't make excess hormones but can grow large and spread out of the pancreas. Symptoms then can be like any of the endocrine pancreatic cancers described above.
Pancreatic cancer may go undetected until it's advanced. By the time symptoms occur, diagnosing pancreatic cancer is usually relatively straightforward. Unfortunately, a cure is rarely possible at that point.
(This section focuses on pancreatic adenocarcinoma, which account for more than 95% of pancreatic cancer. Other forms of pancreatic cancer are mentioned at the end.)
Diagnosing pancreatic cancer usually happens when someone comes to the doctor after experiencing weeks or months of symptoms. Pancreatic cancer symptoms frequently include abdominal pain, weight loss, itching, or jaundice (yellow skin). A doctor then embarks on a search for the cause, using the tools of the trade:
By taking a medical history, a doctor learns the story of the illness, such as the time of onset, nature and location of pain, smoking history, and other medical problems.
During a physical exam, a doctor might feel a mass in the abdomen and notice swollen lymph nodes in the neck, jaundiced skin, or weight loss.
Lab tests may show evidence that bile flow is being blocked, or other abnormalities.
Based on a person's exam, lab tests, and description of symptoms, a doctor often orders an imaging test:
Computed tomography (CT scan): A scanner takes multiple X-ray pictures, and a computer reconstructs them into detailed images of the inside of the abdomen. A CT scan helps doctors make a pancreatic cancer diagnosis.
Magnetic resonance imaging (MRI): Using magnetic waves, a scanner creates detailed images of the abdomen, in particular the area around the pancreas, liver, and gallbladder.
Ultrasound: Harmless sound waves reflected off organs in the belly create images, potentially helping doctors make a pancreatic cancerdiagnosis.
Positron emission tomography (PET scan): Radioactive glucose injected into the veins is absorbed by cancer cells. PET scans may help determine the degree of pancreatic cancer spread.
If imaging studies detect a mass in the pancreas, a pancreatic cancerdiagnosis is likely, but not definite. Only a biopsy -- taking actual tissue from the mass -- can diagnose pancreatic cancer. Biopsies can be performed in several ways:
Percutaneous needle biopsy: Under imaging guidance, a radiologist inserts a needle into the mass, capturing some tissue. This procedure is also called a fine needle aspiration (FNA).
Endoscopic retrograde cholangiopancreatography (ERCP): A flexible tube with a camera and other tools on its end (endoscope) is put through the mouth to the small intestine, near the pancreas. ERCP can collect images from the area, as well as take a small biopsy with a brush.
Endoscopic ultrasound: Similar to ERCP, an endoscope is placed near the pancreas. An ultrasound probe on the endoscope locates the mass, and a needle on the endoscope plucks some tissue from the mass.
Laparoscopy is a surgical procedure that uses several small incisions. Using laparoscopy, a surgeon can collect tissue for biopsy, as well as see inside the abdomen to determine if pancreatic cancer has spread. However, laparoscopy has higher risks than other biopsy approaches.
If pancreatic cancer seems very likely, and the tumor appears removable by surgery, doctors may recommend surgery without a biopsy.
Treating pancreatic cancer is challenging when it's discovered at an advanced stage, as is usually the case. Researchers are seeking methods of early detection, but so far none has proved useful. These methods include:
Blood tests. Certain substances, such as carcinoembryonic antigen (CEA) and CA 19-9, are elevated in people with pancreatic cancer. However, blood tests don't allow for early detection of pancreatic cancer, because these levels may not rise until pancreatic cancer is advanced, if at all.
Endoscopic ultrasound. Some families have multiple members affected by pancreatic cancer. The American Cancer Society says that up to 10% of pancreatic cancers may be caused by inherited DNA changes. Studies are ongoing to see if aggressive screening with endoscopic ultrasound works for early detection of pancreatic cancer in healthy family members. Early results are promising. However, endoscopy is an invasive procedure, so its use is only justified in people already at high risk for pancreatic cancer.
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